One thing that 1E has over some of the later Es is the plethora of visions. There was infravision and ultravision, which survive mutated into darkvision and low-light vision. Some monsters, such as the Fiend Folio‘s nycadaemon had x-ray vision, gamma vision, and indeed a vision for every part of the electromagnetic spectrum. Imagine cosmic ray vision, radio wave vision, and microwave vision. Pretty whacky, huh?

As I mentioned in S Is for Snakes, many snakes are sensitive to the infrared portion of the spectrum, but the Pathfinder Roleplaying Game doesn’t really have rules to simulate such heat sensitivity. And more exotic visions, such as gamma vision? Forget about that!

Or, if forgetting about it isn’t your cup of tea, take a gander at these completely unplaytested and only vaguely scientifically accurate rules:

X-Ray Vision

Some monsters have x-ray vision, although this is a slight misnomer. These monsters don’t so much as just see x-rays the way the human eye “sees” visible light. Instead the monsters’ eyes actually project low levels of x-rays by which they can see through certain materials. Glomming text from the ring of x-ray vision is a good place to start.
X-ray vision gives a creature the ability to see into and through solid matter. Vision range is 20 feet, with the creature seeing as if it were looking at something in normal light even if there is no illumination. X-ray vision can penetrate 1 foot of stone, 1 inch of common metal, or up to 3 feet of wood or dirt. Thicker substances or a thin sheet of lead blocks the vision. Among its obvious uses, x-ray vision makes defeating conventional disguises child’s play.

“Nice mask you got there,” said the nycadaemon. “Shame you didn’t line it with lead. Of course, then I’d wonder why you’d wrapped your face with lead, but, hey, no plan’s perfect.”

Infravision

A creature with infravision sees variations in heat. This sort of vision is especially good at detecting creatures that generate their own body heat, such as most humanoids. (Are lizard folk cold-blooded? What about frost giants?) Detection is even possible through solid matter.

Infravision works just like normal sight in terms of range, complete with appropriate Perception check penalties for distance. Heat signatures can be detected through up to 1/2 foot of stone, 1 inch of common metal, or up to 1 foot of wood or dirt. Thicker substances block heat signatures, although extreme heat sources may be visible through thicker substances at the GM’s discretion.

A creature with infravision can also track the residual heat of a quarry’s foot steps. The base Survival DC for tracking a heat signature is 10, but it rapidly increases by +2 per minute that has passed since the tracks were made. Certain environmental conditions, such as a forest fire or shifting desert sands, may further increase the DC or even make such tracking impossible, at the GM’s discretion.

Sudden exposure to extreme heat can dazzle a creature relying on infravision. The creature must make a DC 15 Fortitude save to avoid being dazzled for 1 round. If the extreme heat persists, it would be appropriate to have the creature remain dazzled as long as it remains in the area. For example, an infravision using giant snake is tracking its prey, a druid. The druid lures the snake into an ambush zone, and then uses some appropriate fire spell to ignite a bonfire. The snake fails its Fortitude save and becomes dazzled as long as it remains within the full illumination area of the bonfire.

More Exotic Vision Traits

Other types of more exotic vision, such as gamma vision, could work like x-ray vision, only moreso. Odd side effects could also result. Since gamma rays will pass right through a mirror, a creature relying on solely gamma vision couldn’t see a reflection. Would this, perhaps, also impart some sort of resistance or immunity to certain illusions? For that matter, would x-ray vision or infravision do so?